Door for byproduct horizontal coke oven



Dec. 22', 1964 w. CREMER ETAL I 3,152,584

DOOR FOR BYPRODUST HORIZONTAL COKE OVEN Filed Sept. 19, 1961 2 Sheets-Sheet 1' IN V EN TORS. [VAL TEE HE KAIZLEQOL KSNKE T 57' By 2 2 026 IVE/$546171 azi fi @234.

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1964 w. CREMER ETAL 3,162,584 DOOR FOR BYPRODUCT HORIZONTAL COKE OVEN Filed Sept. 19 1961 2 Sheets-Sheet 2 INVENTORS. WALTER CREME? K/NQL KOLKS United States Patent 3,162,534 1300K FOR BYPRODUCT HGRIZENTAL COKE EVEN Wflter Cremer, Karl Kollrs, Waiter Stanlre, and Georg Henseleit, Essen, Germany; Anna Theresia Henseleit, sole heir of said Georg Henseleit, deceased, assignors, by mesne assignments, to Koppers Company, line, Pittsburgh, Pa, a corporation of Delaware Filed Sept. 19, 1961, Ser. No. 139,270 16 Claims. (Cl. 202--248) The invention relates to a door for byproduct coke ovens with horizontal coking chambers, which are provided with inclined, downwardly arranged door supporting latch levers which are fastened to the body of the door and which, uponhanging the door in place at the end of a coking chamber, engage in door fastening hooks arranged on the body of the oven, so that the door with its sealing frame or edge is brought by the doors own weight tightly adjacent to the sealing surface of the oven frame.

Coke oven doors are known in which the pressure of the sealing frame on the door against the sealing surface on the oven frame is elfected by the weight of the door on door supporting latch levers fastened on the body of the door; said door supporting latch levers have an inclined, downwardly directed position and, upon hanging the door in place, form by engagement in a door hook arranged on the body of the oven, the support for transmitting the actual weight of the door as the effective sealing pressure.

In coke oven doors it is necessary to produce on all sides a uniform pressure of the flexible sealing frame or edge against its sealing surface on the oven. In known doors in which the pressure is effected by the actual weight of the door, with the support for the door supporting latch levers on the body of the door, the requisite uniform pressure is not always assured such that, on hanging the door, pressure differences do not occur between the door supporting latch levers mounted on the upper and those mounted on the lower parts of the door with their respective door hooks arranged on the body of the oven, when the distance between the door hooks cannot be accurately maintained for placement thereof opposite the door supporting latch levers. Furthermore, diflerences in the positions of the door hooks relative to the latch levers can occur during operation as the result of warping of the door or warping of the oven reinforcement (not shown) by expansion. When this displacement occurs different sealing pressures arise and consequently leaks result.

This invention consists in providing a crank shaft and crank arm as the supporting crank levers, which levers engage in the door fastening hooks on the body of the oven, upon hanging the door, and wherein the crank shaft and arm are fastened to the body of the door; by mounting the crank arms and shaft thereon by means of a convex rocking bearing eccentrically disposed in a regulable bushing.

By such a design and arrangement of the door supporting latch levers wherein cnank arms on shafts are employed at the upper and lower parts of the door, it is possible, after hanging the doors, to adjust the latch levers independently of one another. This adjustment is effected by means of a bushing having an eccentric bearing surface for receiving the shaft. With this adjusting means the exact position of both of the door supporting latch levers at the upper and lower parts of the door can be set and thereby assure uniform sealing pressure. sure is maintained every time the door is hung. Subsequent adjustment during operation is necessary only in Thereafter, the established uniform sealing pres ice case any warping of the door or of the oven frame occurs in the course of the operation of the oven or in case differences in relative positions between the upper and lower crank arms occur as a result of other circumstances.

By the convex design of the bushing for the shaft of the crank arms and of the joint between the arms and the bushing, an equalization for the uniform engagement of the crank arms in the door hooks is achieved in the horizontal plane, so that a uniform pressure is assured both in the vertical as well as in the horizontal plane.

A further feature of the invention is to provide a door as aforesaid in which the irregularities of the bolts on the body of the door in respect to the door fastening hooks on the body of the oven are automatically adjusted so that a uniform pressure is assured at all latches.

Accordingly, the invention provides as a further feature an upper bearing for supporting the upper door latch lever that is arranged on the body of the door and is freely vertically movable within fixed limits. This upper bearing is acted upon by vertically-acting pressure springs which assist the sealing pressure of the door; and the door lifting claws of the door operating apparatus are disposed to liftably engage the movable upper supporting lever bearings on such doors.

The upper supporting lever bearing is pressed downward by the pressure springs when the door is in the closed position and in the course of this downward ap plication of force the upper supporting lever braced at the fastening hooks on the door frame assists the sealing of the door by the pressure of its own weight. Compensation for irregularities in the position of the supporting lever in respect to the fastening hooks on the door frame is thus provided by the movable bearings.

According to another characteristic of this latter feature of the invention the bearing for the lower supporting lever is stationary and only the upper supporting lever bearing or bearings are movably arranged on the body of the door. The upper and lower door lifting claws of the door operating apparatus are arranged at such a distance from one another that the upper door lifting claw first engages the freely movable bearing for the upper supporting lever at its underside, whereby the pressure spring therefor is somewhat compressed and the upper supporting lever is lifted from the door fastening hooks 0n the door frame. Thereafter the lower door lifting claw becomes engaged and the door is listed. Thus, freedom of motion of the bearing for the lower supporting lever is unnecessary. Furthermore, because the hearing for the lower stationary supporting lever is fixed, the door is prevented from settling to the base of the oven chamber and remains in its suspended position in the door frame.

A still further object or aspect of the invention is the connection provided between the upper lifting lever and the lower lifting lever of the door operating apparatus, comprising a connecting rod and an angular lever, or bell-crank, which is pivotally mounted on the lower door lifting lever for movement in the direction of the oven chamber, for the purpose of moving the claw of the lower lifting lever toward and away from the door. Upon inserting the door, the sealing edge on the door is first fitted with certainty against the door frame on the oven at the lower part, so that the lower supporting lever on the door engages in the fastening hooks on the door frame even in the case of a somewhat inwardly directed, inclined position of the door frame of the oven chamber during the operating period. Any difference in the relative positions of the lower and upper supporting levers is taken up in the movable bearing and consequently at the upper supporting lever by the pressure effect of the pressure spring exerted after lowering the door lifting claws.

eccentric bushing 12.

v the movement of their crank arms The invention is illustrated in the drawing by way of three examples:

FIG. 1 is a Vertical section through the lower part of a coke oven door constructed in accordance with the invention.

FIG. 2 shows a horizontal section along line II-II of FIG. 1.

FIG. 3 schematically illustrates the arrangement of the crank arms of another embodiment on a door as in. FIG. 1.

FIG. 4 is a partial vertical section through a door constructed with the bearings, freely movable within limits, for the upper levers according to the invention.

FIG. 5 illustrates a front view of the doorshown in FIG. 4. o v

The same characters of reference designate the same parts in each of the several views of the drawings.

Referring to FIGS. 1 to 3:

The door plug 1 projecting into the horizontal byproduct oven chamber is fastened on a metallic supporting frame 2 which is connected with the cast-iron main body section .3 of the door- The main door section 3 has along each side thereof a projecting peripheral flange frame 4 having a U-shaped channel 5 formed thereon, in which channel in gastight relation therewith is mounted aZ-shaped flexible sealing edge 6.

V In the closed position of thedoor the sealin'g edge 6 is pressed against the sealing surface 7 'of. coke-oven door frame 9, fastened to the masonry body 8 of the oven. A door hook 11 against which the stub-shaft or pin 14 of crank lever 13 seats is mounted on each side of the door on door frame 9 (not illustrated detail) adjacent to the masonry body 8 of the oven. The arms 13 of crank lever 13 are mounted on ashaft 12 which in turn is supported in. a bearing bushing 12 formed with its bore having an inwardly convex surfaceprovid ing a rocking hearing located eccentrically of the bushing 12. The bushing 1?.v is located in a two-piece hearing shell 15 which is rigidly connected to the metallic door section3. p

Crank arms 13 whose ends 17 are connected with the pins 14 for engam'ng in the door hooks 11 are fastened on the ends of crank shaft ij't which The arms 13 have a downwardly directed, inclined position, the lowest position which they assume after lifting out the door being limited. by set screws 19. Each set screw 19 is adjustable in projection 21 located on one of each of the pairs of ends 17, and serves to limit the inclined position assumedof the arms 13 by contacting the side flanges 4 of the metallic door section 3.

In addition to the-arrangement of the crank lever 13 and the door-hooks 11, as illustrated in FIG. 1, for the lower part of the. door the same arrangement is also provided in the upper part of the door (not illustrated, in

FIGS. lto 3).. The door'is loweredvfrom above to. place the sealingrirn edge 6 in front of the sealing sur-' 4 I V 7 parent that the sealing pressure is different in the upper and lower parts of the door.

Differences that may exist in the arrangement of the two opposite door hooks 11 are equalized by the rocking bearing action afforded by the convex construction of the inner wall of the eccentric bushing 12, since the ends of both pins 14 of the crank arms 13 adjust to these onevennesses in a fashion similar to a balance beam.

The crank levers 13 can also be mounted to interconnect with the fastening hooks 11 as in the modification illustrated in FIG. 3. 7

Furthermore, a continuous bent rod may also be provided as the crank lever 13 in place of the separate crank pins 14 and arms 13*.

' Referring to FIGS, 4 and 5 The door plug 1, which is refractory and projects into the oven, is held by an inner metallic supporting frame 2. The supporting frame 2 is firmly connected with the main part 3 as the body of the door. The body part 3 of the door is provided with a peripheral projecting flanged frame 4, having the U-shaped channel 5 formed thereon. Engaged in Urshaped channel 5 in gas-tight relationship is Z-shaped,'ficxib'le sealing edge 6.

In'the closed position of the door, the sealing edge 6 is pressed'against sealing surface 7 of'the metallic oven door frame 9 which is fastened to the masonry body 8 of the oven in order to seal the oven chamber from the outside air. Upper fastening hooks 10 and lower fasteninghooks 11 are firmly connected to the door frame 9 of the oven chamber in the area of the upper and lower door parts, respectively. A bushing 12, in which supporting crank lever 13 is mounted, is firmly supported in the fixed two-piece lower bearing shell, or housing, 15 mounted on the lower part of the body 3 of the door. The lower supporting lever 13 is constructed in the form of a crank shaft having crank arms 13 shaft 12 and pins 14, which engage in fixed lower fastening hooks 11 I on the door frame 9 in the closedpositionof the door.

projects from the Upper supporting lever bearing 15 is mohnted on the upper part of the door for free vertical movement within fixed limits. The upper supporting lever bearing 15 is freely movable in guide strips 16 which are fastened to the body 3 of the door and which are provided with a lower limit 27 to limit the downward movement of the upper bearing 15. A pressure spring 31, preferably consisting of a cup spring, is mounted 'by means of bolt 39 between horizontal flange 28 of the body 3 of the door and projecting flange 29 formed on the supporting lever bearing 15% An' upper cranklever '13, the pins 14 of which engage in fixed upper fastening hooks 10 in the closed position of the door, is mounted in bushing 12 supported on the upper supporting lever bearing 15 face'l of the door frame'9, whereby the pins 14 of the arms 13 engage in the door hook 11 and are supported thereon. The door then slides by its own weight some- 1 what towards. the bottom so that the sealing rim edge 6 is forced against sealing surface '7. on the oven door frame 9 by the arrested movement of the pins 14 against, and

-- parts of the door." For this purpose recesses 21 are arrangedin.bushings 12 for engagement by a wrench. The adjusted position'of the eccentric bushing 12' can.

be secured by a set screw 22. A readjustment is then necessary only in thecou'rse of time, when'it becomes ap- 13? away from, the

' The door is inserted and lifted out of the door frame 9 upper lifting lever 33 is pivotally mounted at 34 in the upper part of the door lifting machine 32. lower lift-. ing lever 361s pivotally mounted at '35 beneath the upper double arm lever 33, The levers 33, 36, are provided with claws 37, 38. During the operation of lifting the door, the upper claw 37 engages with downwardly directed projection 39 formed on movable supporting; lever hearing 15 and the lower claw 38 engages with "a stationary strip or bar '40 fixedly mounted on the body 3 of the door.

Levers 33, 36 are interconnected byconnecting rod 41 andfangular lever bell-crank which is pivotally linked to lever'36 at 43, ,1The lower leverarm of the angular lever 42 is connected by rneans of an arm 44 to the claw 38 whioh clawfid' is movably mounted on the end of lower .lifting lever 36,- Any movement oflthe upper lever .of bell-crank; 4r will. move arm 44 and thereby move claw rtin V lever:

age of the pressure spring 31 the claw 37 can be removed from engagement with the upper portion of bearing by moving claw 37 down against the lower strip portion 46 and can thus exert additional equalizing pressing motion on the bearing 15 and arms 13*.

The door body 3 is lifted off the door frame 9 by downward motion of arm 47 of double arm lever 33, whereby the lower lever 36 is lifted against the door body 3 in an easy swinging motion by means of the connecting rod 41. For lifting the door the supporting lever bearing 15 is first moved upward a small amount by the upper door lifting claw 37 resulting in slight compression of pressure spring 31. Then the door is lifted off the door frame 9 by the subsequent engagement of the lower door lifting claw 38 with stationary lifting strip 40 on the door, after which the arms 14, 14 of lower and upper supporting levers 13 respectively are released from the door frame fastening hooks 10, 11.

Upon inserting the door in the door frame 9, claw 38 is advanced in the direction of the oven chamber ahead of the upper claw 37 by the action of angular lever 42, and the effect of the slightly inclined position of the door. The door is first fitted into place at the bottom so that the arms 14 of the lower supporting lever 13 are positively inserted into the lower fastening hooks 11 and as claws 37, 38, are lowered further, the arms 14 of the upper supporting lever 13 become engaged in the upper fastening hooks 10. The pressure spring 31 then moves bearing i5 downwardly, whereby the sealing pressure of the sealing edge 6 against the door frame 9 of the oven chamber is assisted promoting the adjustment of sealing edge 6 to the irregularities in the position of the fastening hooks 11, 10, opposite lower and upper supporting levers 13 respectively in addition to the pressure effected by the actual weight of the door.

More than two supporting levers 13 may be arranged at different elevations in the case of high byproduct ovens. In this case the lower supporting lever bearing is stationary and the other upper supporting lever bearings have the limited freedom of vertical movement described in connection with bearing 15 The inclined position assumed by the supporting levers 13 is limited in the downward direction by suitable, preferably adjustable stops (not illustrated).

We claim:

1. In a closure device for a door for a horizontal coking chamber of a byproduct coke oven wherein said door has a plurality of inclined, downwardly arranged door-supporting latch levers fastened along a portion thereof to the body of the door and engaging at their distal ends against door fastening members on the body of the oven during placement of the door into juxtaposition with a doorway at the horizontal end of the coking chamber, and said door further has a sealing edge which is brought into sealing engagement with a sealing surface on the frame of the oven doorway by the weight of the door itself, the improvement comprising:

(a) each door-supporting latch lever being constructed in the form of a crank having a pair of crank arms joined by a shaft,

(17) a plurality of bushings mounted on said body of the door,

(1) each of said latch levers being rotatably supported in one of said bushings and (2) each of said bushings having an off-center bore therethrough and the surface of the shaft of the latch lever received therein being in contact with the surface of the bore and one of said surfaces being curved in the direction of the longitudinal central axis of said bore and (c) means for selectively adjusting each of said bushings around the longitudinal central axis thereof to axially relocate the shaft of the latch lever supported therein to alter the efiective length of the crank arms between said shaft and the opposing door fastening members on the body of the oven, whereby after initial adjustment of said bushing with said adjusting means, said latch levers are self-adjusting to insure the exertion of uniform sealing pressure between said sealing edge and said sealing surface under the weight of the door itself.

2. A coke oven door as claimed in claim 1, and in which the doorssupporting crank latch levers are suspended in the fastening members and are inclined downwardly toward the bottom of the door in the closed position of the door.

3. A coke oven door as claimed in claim 1, and in which an attachment with a set screw is provided on the outer part of the crank arm in position thereon for the set screw to engage a part on the door, to limit the downward movement of the crank arms to a position at which the arm is always at a location for engaging said door fastening members, when the door is lifted from said door fastening members.

4. In a system for sealing and unsealing coke oven doors wherein a door handling machine having a plurality of interconnected power actuated forwardly projecting door carrying levers are engageable with a plurality of inclined downwardly arranged door-supporting latch levers fastened along a portion thereof to the body of the door and engaged at the distal ends thereof against door fastening members on the body of the oven during placement of the door into juxtaposition with a doorway at the horizontal end of the coking chamber and said door further has a sealing edge which is brought into sealing engagement with a sealing surface on the frame of the oven doorway by the weight of the door itself, the combination with said door latching levers of:

(a) a bearing for at least one supporting latch lever,

(1) said bearing being freely vertically movable within fixed limits and being slidably mounted on said body of said door,

(b) a vertically-acting pressure spring mounted on said body of said door biasing said bearing downward,

(c) a horizontally-disposed bar rigidly affixed to said body of said door,

(11') a first door-carrying lever mounted on said machine in a position to coact with said movable bear- 111g,

(1) said first door-carrying lever having a claw formed integral therewith on the distal end thereof,

(e) a second door-carrying lever mounted on said machine in a position to coact with said rigidly affixed bar during coaction between said first door-carrying lever and said movable bearing,

(1) said second door-carrying lever being longitudinally extensible, and

(f) means interconnecting said first and second doorcarrying levers for extending and contracting said second door-carrying lever,

(1) said extending and contracting means being automatically actuated by movement of said first door-carrying lever.

5. Apparatus for sealing and unsealing coke oven doors substantially as recited in claim 4, in which the first and second door-carrying levers are interconnected with each other by a connecting rod and an angular lever pivotally mounted on the lower lever for extension of the second door-carrying lever in the direction of the door upon lifting movement of the first door-carrying lever.

6. Apparatus for sealing and unsealing coke oven doors as claimed in claim 4 wherein the plurality of door-supporting leversinclude an upper and a lower door-supporting lever, a stationary bearing is provided for the lower door-supporting lever and only the bearing for the upper door-supporting lever is vertically movable;

7. Apparatus for latching and unlatching a coke oven door wherein said door has a main body section, a pe- (1) one of said upper members being disposed to either side of said door opening, (b) a pair of lower retaining members affixed to and projecting from the coke oven structure,

(1) one of said lower members being disposed to either side of said door opening,

(c') a first supporting bushing mounted on the upperv part of said main body section, I

(d) asecondsupporting bushing afiixed part of said main body section,

(1) said first and second bushings each having an off-center bore extending therethrough,

(e) first and second self-adjustable crank levers rotatably supported in the bores of said first and second bushings respectively, I

(l) the surface of each of said crank levers housed within said bores being in contact with the surface of the respective bore and one of said surfaces being curved in the direction of the longitudinal central axis of said bore, and

(f) means for adjusting each of said bushingsaround the longitudinal central axis'thereof to shift the latch lever supported therein,

whereby after initial adjustment of said bearings with said adjusting means said latch levers are self-adjusting to to the lower insure the exertion of uniform sealing pressure between 1 said sealing edge and said sealing surface under theweight of the door itself. w v V t 8. Apparatus for latching and unlatching' a coke oven door substantially as recited in claim 7 wherein the offcenter bores are of varying internal diameter.

9. Apparatus for latching and unlatching a coke oven door substantially as recited in claim 7 wherein, each of the oifcenter bores have an inwardly convex surface.

10. Apparatus for latching and unlatching a coke oven door wherein said door has a main body section, a peripheral flange frame integral therewith and projecting therefrom and means extending around the periphery of said flange for sealing against a sealing surface on the coke oven structure around the opening for-said door, said latching and unlatching apparatus comprising:

(a) a pair of upper retaining members affixed'to and projecting from the coke oven structure," 7

(1) one of said upper members being disposed to either side of'said door opening, (b) a pair of lower'retaining members affixed to and projecting "from the coke oven structure,

(1) one of said lower members being disposed to either side of said door opening, (c) a first supporting bearing mounted on'the upper part of said main body section, i

(1) said first bearing being movable in a substantially vertical direction vrelative to said, main body section,

(d) a second supporting bearing affixed to the lower 1 part of said main body section, a

( 1) said first and second bearings each-having an i ofi-center bore extending therethrough,

Tie first and second self-adjustable crank levers rotatbly supported in the boresof saidiirst-and second bearings respectively, p t H 1(1) the; surface of eachfof said crank levers housed within said bores being in contact with:

r a, a 8 the longitudinal central axis thereof to shift the latch leversupported therein, whereby after initial adjustment of said bearings withsaid adjusting means'sa'id latch levers are self-adjusting to in sure the exertion of uniform sealing pressure between said sealing edge and said sealing surface under the weight of the door itself.

ll. Apparatus for latching and unlatching a coke oven door substantially'as recited in claim 10 wherein the ofie center bores are each of varying internal diameter.

12. Apparatus for latching and unlatching a coke oven door substantially as recited in claim 10 wherein each of said off-center bores has an inwardly convex surface.

13. Apparatus for latching and unlatching a coke oven door wherein said door has a main body section, a pcripheral flange frame inte ral therewith and projecting therefrom and means extending around the periphery of said flange for sealing against a sealing surface on the coke oven structure around the opening for said door, said latching and unlatching apparatus comprising:

(a) a pair of lower retaining members affixed to and projecting from the coke oven structure,

(1-) one of said upper members being disposed to either side of said door opening,

(12) a pair of lower retaining members affixed to and projecting from the coke oven structure,

(1) one of said lower members being disposed to either side of said door opening,

(c) a first supporting bearing mounted on the upper part of said main body section,

(1) said first bearing being movable in a substantially vertical direction relative to said main body section, V (d) means connected between said main body section and said first bearing for biasing said first bearing downwardly, (e) a second supporting bearing afiixed to the lower part of said main body section,

Y (1) .each of said bearings having an off-center bore extending therethrough, I (i), first and second self-adjustable crank levers rotatably supported in the bores of said first and second 7 bearings respectively, 1) 'the surface of each of said crank levers housed within said bores being in contact with the surface of the respective bore and one of said surfaces being curved in the direction of I the longitudinal central axis of said bore, and (g) means for adjusting each of said bearings around the longitudinal central axis thereof to shift the latch lever supported therein, 1 whereby after initial adjustment oftsaid bearings with said adjusting means said'latch levers are self-adjusting to in: sure the exertion of uniform sealing pressure between said sealing edge and said sealing surface under the weight of the door itself.

14. Apparatus for latching and unlatchinga coke oven door substantially as recited in claim l3 wherein each off- ,7 center bore has an inwardly, convex surface and the biasing I gmcans'is a pressure spring.

r 16. Apparatus for latching and unlatching a coke oven door wherein said door has amain body section, a peripheral flange frame integral therewith and projecting there-f from and means extending around the periphery of said; flange for sealing against a sealing; surface on the coke oven structure around theopening for said door, said latch ing'an'd unlat chi'ng apparatus comprising:

. the surface of the respective bore andoneof said surfaces being, curved in the'direction-of 1 H the longitudinal cent-ralzaxis ofisaid bore, and. (7) means for adjusting each; of saidfbearings around;-

' (r a pair of upper retaining members afiixe'd to and,

' projecting from'the coke oven structure,

- (I) one of said upper members being disposed 'to I Q either'side of said doo-rlopening, I e

(b) a pair of lower retaining members aflixed to and projecting from the coke oven structure,

(1) one of said lower members being disposed to either side of said door opening,

(c) a first supporting bearing housing mounted on the upper part of said main body section,

(1) said first bearing housing being movable in a substantially vertical direction relative to said main body section,

(d) a second supporting bearing housing affixed to the lower part of said main body section,

(e) first and second bushings mounted in said first and second bearing housings respectively,

(1) each of said bushings having an off-center bore extending therethrough,

(f) first and second self-adjustable crank levers rotatably supported in the bores of said first and second bushings respectively,

(1) the surface of each of said crank levers housed 1% within said bores being in contact with the surface of the respective bore and one of said surfaces being curved in the direction of the longitudinal central axis of said bore, and (g) means for adjusting each of said bushings around the longitudinal central axis thereof to axially relocate the latch lever supported therein, whereby after initial adjustment of said bearings With said adjusting means said latch levers are self-adjusting to insure the exertion of uniform sealing pressure between said sealing edge and said sealing surface under the weight of the door itself.

References Cited in the file of this patent UNITED STATES PATENTS 1,744,118 Hicks Jan. 21, 1930 1,251,541 Grasshofi Aug. 5, 1941 2,772,226 Doll Nov. 27, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 5 162 584 December 22 1964 Walter Cremer et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8, line 21, for "lower" read upper Signed and sealed this 18th day of October 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. IN A CLOSURE DEVICE FOR A DOOR FOR A HORIZONTAL COKING CHAMBER OF A BYPRODUCT COKE OVEN WHEREIN SAID DOOR HAS A PLURALITY OF INCLINED, DOWNWARDLY ARRANGED DOOR-SUPPORTING LATCH LEVERS FASTENED ALONG A PORTION THEREOF TO THE BODY OF THE DOOR AND ENGAGING AT THEIR DISTAL ENDS AGAINST DOOR FASTENING MEMBERS ON THE BODY OF THE OVEN DURING PLACEMENT OF THE DOOR INTO JUXTAPOSITION WITH A DOORWAY AT THE HORIZONTAL END OF THE COKING CHAMBER, AND SAID DOOR FUTHER HAS A SEALING EDGE WHICH IS BROUGHT INTO SEALING ENGAGEMENT WITH A SEALING SURFACE ON THE FRAME OF THE OVEN DOORWAY BY THE WEIGHT OF THE DOOR ITSELF, THE IMPROVEMENT COMPRISING: (A) EACH DOOR-SUPPORTING LATCH LEVER BEING CONSTRUCTED IN THE FORM OF A CRANK HAVING A PAIR OF CRANK ARMS JOINED BY A SHAFT, (B) A PLURALITY OF BUSHINGS MOUNTED ON SAID BODY OF THE DOOR, (1) EACH OF SAID LATCH LEVERS BEING ROTATABLY SUPPORTED IN ONE OF SAID BUSHINGS AND (2) EACH OF SAID BUSHINGS HAVING AN OFF-CENTER BORE THERETHOUGH AND THE SURFACE OF THE SHAFT OF THE LATCH LEVER RECEIVED THEREIN BEING IN CONTACT WITH THE SURFACE OF THE BORE AND ONE OF SAID SURFACES BEING CURVED IN THE DIRECTION OF THE LONGITUDINAL CENTRAL AXIS OF SAID BORE AND (C) MEANS FOR SELECTIVELY ADJUSTING EACH OF SAID BUSHINGS AROUND THE LONGITUDINAL CENTRAL AXIS THEREOF TO AXIALLY RELOCATE THE SHAFT OF THE LATCH LEVER SUPPORTED THEREIN TO ALTER THE EFFECTIVE LENGTH OF THE CRANK ARMS BETWEEN SAID SHAFT AND THE OPPOSING DOOR FASTENING MEMBERS ON THE BODY OF THE OVEN, WHEREBY AFTER INITIAL ADJUSTMENT OF SAID BUSHING WITH SAID ADJUSTING MEANS, SAID LATCH LEVERS ARE SELF-ADJUSTING TO INSURE THE EXERTION OF UNIFORM SEALING PRESSURE BETWEEN SAID SEALING EDGE AND SAID SEALING SURFACE UNDER THE WEIGHT OF THE DOOR ITSELF. 